Air-ventilated shoe sole

ABSTRACT

A mid-sole body has air inlet openings in the heel section and air outlet openings in the midfoot section and/or ball/toe section. The air inlet openings are connected to the air outlet openings via a ventilation channel. The ventilation channel is covered by a cover which is elastically resilient in the direction of the outsole during walking when under strain. The shoe is force-ventilated due to the rolling off of the shoe having such a shoe sole during walking and heat is removed from the shoe sole.

The present invention relates to a shoe sole according to the preamble of patent claim 1 and to a walking device with a shoe sole according to claim 13.

A special shoe sole structure for walking devices is known by the name “Masai Barefoot Technology”, MBT for short, and also known under the Swiss Masai label. A characteristic feature of the MBT is a form of sole that is rounded convexly in the walking direction, with an inserted soft heel part, known as the “Masai sensor”. The midsole has a reinforcing element—known as a “shank”—integrated in it, which reinforces the midsole in such a way that it is substantially flexurally rigid even in the portion thereof that is above the soft heel part. The shoe sole structure of the MBT walking device, deliberately soft and made to act in a destabilizing manner for this reason, means that the foot loses the hold and support that is characteristic of physiological locomotion. This has an impact on major parts of the postural and supporting musculature, because the body must now be actively kept in balance. On account of these constantly required minimal compensating movements and adaptations of the musculature of the foot in seeking to maintain a stable standing position, wearing MBT walking devices achieves the effect of performing a kind of permanent coordination training and works additional parts of the musculature of the skeleton. In particular, neglected muscles are trained, posture and gait pattern are improved and the body is toned and shaped. Furthermore, wearing MBT walking devices can alleviate back, hip, leg and foot ailments and joint, muscle, ligament or tendon injuries as well as relieve hip and knee joints. On the one hand, the MBT walking device leads to improved blood circulation, and consequently to the foot being heated up, and, on the other hand, the shoe sole has a considerable thickness, with correspondingly good thermal insulating properties. There is therefore a need to provide a shoe sole that is better able to remove heat.

There is also the same need for shoe soles of a different structure, in particular shoe soles for sport shoes. For example, shoes of the “ClimaCool” series from the Adidas company have air openings on the sole.

An object of the present invention is to provide a shoe sole that has improved heat removal properties.

This object is achieved by a shoe sole that has the features of patent claim 1.

A midsole body has at least one air inlet opening in the heel region, and air outlet openings in the midfoot region and/or in the ball/toe region. The air inlet opening and the air outlet openings are connected to one another by means of a ventilation channel. This is covered by a cover on the side of the midsole body that is facing away from the outsole—on the upper side of said midsole body. This cover is elastically compliant, in the direction of the outsole, when under load during walking. Since the cover is elastic, it returns to its original form again when the load is relieved.

Consequently, the rolling motion during walking inevitably causes a constant exchange of air in the shoe sole, which leads to improved heat dissipation. The air ventilation thereby enforced has the effect that air enters the shoe sole through the air inlet opening and leaves again at the air outlet openings, which counteracts a buildup of heated air under the foot.

The heated air in the ventilation channel is forced through the air outlet openings by the compression of the sole, or the cover thereof, when the heel is put down, in a way corresponding to the subsequent rolling motion. In the course of the rolling motion, the heel region is relieved of load, which leads to fresh air being sucked into the ventilation channel through the air inlet opening. A rolling motion that is optimal for this purely mechanical principle, and associated optimal air ventilation, are achieved with shoe soles according to claim 9. With conventional shoe soles, it is unlikely that such efficient air ventilation can be achieved.

Further preferred embodiments of the shoe sole according to the invention are specified in the further dependent patent claims.

The invention is explained in more detail on the basis of exemplary embodiments that are represented in the drawing, in which purely schematically:

FIG. 1 shows a plan view of a midsole body of a shoe sole according to the invention, with two air inlet openings in the heel region, which are flow-connected by way of a ventilation channel to inner and outer air outlet openings in the midfoot region and in the ball/toe region;

FIG. 2 shows a side view of a shoe sole according to the invention, with air inlet openings and air outlet openings that are formed on the midsole body and extend in the direction of the outsole, the midsole body having a heel recess in which a soft heel part is arranged;

FIG. 3 likewise shows a side view of a further embodiment of a shoe sole according to the invention, likewise with a soft heel part arranged in a heel recess of the midsole body, and air inlet and air outlet openings, which however are arranged in an upper peripheral region of the midsole body;

FIG. 4 shows a perspective representation of a preferred embodiment of a cover for the ventilation channel, with an air-permeable carrier layer and double-conical elastic supporting elements protruding from the latter;

FIG. 5 shows, in a representation identical to that of FIG. 4, a further preferred embodiment of the cover, which likewise has an air-permeable carrier layer, from which however elastically deformable wave-shaped supporting strips protrude;

FIG. 6 shows, in a representation identical to that in FIGS. 4 and 5, a further particularly preferred embodiment of the cover, with an air-permeable carrier layer and a supporting layer formed as a knitted spacer fabric;

FIG. 7 shows an exploded representation of a possible embodiment of the shoe sole according to FIG. 2;

FIG. 8 shows a side view of a further possible embodiment of the shoe sole according to FIG. 2;

FIG. 9 shows a plan view of the shoe sole according to FIG. 8, the midsole body being transparent and the ventilation channel being shown colored gray; and

FIG. 10 shows a perspective representation of a reinforcing element of the embodiment according to FIGS. 8 and 9.

FIG. 1 shows a plan view of a midsole body 10 of a midsole 12. It has in a rear portion 14, seen in the walking direction L, of a heel region 16 a respective air inlet opening 22 both on the shoe sole inner side 18 and on the shoe sole outer side 20. The shoe sole inner side 18 should be understood as meaning the side facing the other shoe sole of a pair and the shoe sole outer side 20 should be understood as meaning the side of the shoe sole facing away therefrom.

Furthermore, the midsole body 10 has in a midfoot region 24 and in a ball/toe region 26 in each case five air outlet openings 28, both on the shoe sole inner side and on the shoe sole outer side. Seen in the walking direction L, the midfoot region 24 adjoins the heel region 16 and the ball/toe region 26 adjoins the midfoot region 24, each of these regions extending approximately over one third of the length of the shoe sole.

The air inlet openings 22 and the air outlet openings 28 are connected to one another by way of a ventilation channel 30 formed by a depression in the midsole body 10. This channel has in the heel region 16 a heel portion 32 with two legs 34 arranged in a V-shaped manner. Each of these legs 34 leads to one of the two air inlet openings 22. Adjoining the heel portion 32, the ventilation channel 30 has a distributor portion 36, the main channel portion 38 of which, flow-connected to the legs 34 of the heel portion 32, runs up to the ball/toe region 26, in the longitudinal direction of the shoe S. Seen in the direction at right angles to the longitudinal direction of the shoe S, the main channel portion 38 is offset with respect to the longitudinal center of the shoe in the direction of the shoe sole inner side 18, to run under the inner instep.

Branch channel portions 40 branch off from both sides of the main channel portion 38, each of these branch channel portions 40 running to one of the air outlet openings 28.

Both the air inlet openings 22 and the air outlet openings 28 have a width of preferably at least 4 mm and a length that is preferably at least twice the stated width. Correspondingly, the ventilation channel 30 also has, measured in a direction at right angles to the upper surface 42, on the footbed side, of the midsole body 10, with respect to said surface a depth of preferably at least 4 mm. The width of the ventilation channel 30 is preferably greater everywhere than the depth, preferably at least twice as great.

On the side of the surface 42, the ventilation channel 30 is covered by an elastically compliant cover 52, which is not shown in FIG. 1 but preferred embodiments of which are described in connection with FIGS. 4 to 6.

FIG. 2 shows a side view of a midsole 12 of the shoe sole, the midsole body 10 of which has in the rear portion 14 of the heel region 16—on each of both sides—an air inlet opening 22 and in the midfoot region 24 and the ball/toe region 26 a total of 4 air outlet openings 28, which are arranged successively one behind the other in the longitudinal direction of the shoe S and overlapping in an imbricated manner as a result of their slanted orientation and length. The air inlet opening 22 and the air outlet openings 28 are flow-connected to one another by a ventilation channel 30 in a way corresponding to FIG. 1; this ventilation channel has four branch channel portions 40 on both sides.

The midsole body 10 has on its underside, which is facing an outsole 44, a heel recess 46, in which a soft heel part 48 is arranged. Seen in the longitudinal direction of the shoe S, this soft heel part extends from the rear portion 14 of the heel region 16 to approximately the middle of the midsole 12 and runs over the entire width of the midsole 12 with an at least approximately constant cross section in the form of a convex-convex lens. In the unloaded state, the soft heel part 48 and the midsole body 10 keep the outsole in a form in which it is rounded in a continuously convex manner in the longitudinal direction of the shoe sole S, as is generally known from MBT walking devices. The soft heel part 48 has a greatest thickness of about 20 mm. Correspondingly, the greatest thickness of the midsole body 10 is approximately 30 mm.

It should be mentioned at this point that the midsole body 10 has a peripheral bead 50, which protrudes in the upward direction with respect to the surface 42. On the one hand, this bead serves for fastening the midsole 12 to an upper 56 and on the other hand the aforementioned cover 52 is arranged in the depression delimited by the surface 42 and the bead 50.

The soft heel part is preferably produced from an open-cell polyurethane elastomer foam (PUR Shore 30 C) and the midsole body 10 from a polyurethane elastomer (PUR Shore 58 C) or an ethylene vinyl acetate (EVA); this applies to all the embodiments shown.

FIG. 3 shows a midsole 12 of the shoe sole that is formed identically to that according to FIG. 2, but with the air inlet openings 22 and the air outlet openings 28 now being of an oval form and running in a row one behind the other in an upper peripheral region of the midsole body 10. Here, too, the air inlet openings 22 and the air outlet openings 28 are connected to one another by way of a corresponding ventilation channel 30.

The elastically deformable cover 52 for the ventilation channel 30 is preferably formed by an insole 54, which is placed onto the upper surface 42 of the midsole body 10 and extends on all sides as far as the bead 50 or the upper that is fastened to the midsole body 10 and is lying against the bead 50.

The embodiment of the insole 54 that is shown in FIG. 4 has an upper, air-permeable carrier layer 58, from which supporting elements 60 protrude in the downward direction, in the fitted state toward the midsole body 10, arranged in a grid pattern and at a distance from one another. These supporting elements are preferably formed as double cones and produced from an elastic synthetic material. In their length, they optimally match the depressions in the midsole body 10. In the fitted state, they rest with their free end on the midsole body 10.

A further embodiment of the insole 54 is represented in FIG. 5. It likewise has an upper, air-permeable carrier layer 58. Wave-shaped, elastically deformable supporting strips 62 protrude from it in the downward direction. These strips preferably run in planes that extend at right angles to the carrier layer 58 and parallel to one another. In the fitted state, the supporting strips 62 rest with wave crests facing away from the carrier layer 58 on the midsole body 10.

The supporting elements 60 or the supporting strips 62 consequently form an elastically compliant supporting layer 64 for the carrier layer 58.

In the case of the particularly preferred embodiment of the insole 54 that is shown in FIG. 6, the supporting layer 64 is made in the form of a knitted spacer fabric 66. The upper side forms the air-permeable carrier layer 58 and elastically deformable pile threads, also known as spacer threads, run from these in the downward direction. Knitted fabrics of this type are produced, for example, by the company Müller Textil GmbH, Wiehl-Drabenderhöhe (DE) and are marketed under the name “3mesh”. Possible embodiments of the spacer fabric 66 are disclosed, for example, in EP 1 775 362 A and EP 1 860 218 A.

An exploded perspective representation of a preferred embodiment of the shoe sole according to FIG. 2 is shown in FIG. 7. The midsole body 10 is provided with the heel recess 46. The soft heel part 48 is inserted in the heel recess 46, in the present case filling the space. As known from MBT walking devices, the outsole 44 is fastened to the midsole body 10 and the soft heel part 48, whereby it is kept in the convex form, compare FIGS. 2 and 3. It consists, for example, of rubber and has a Shore A hardness of 55 to 65.

A ventilation insert element 68, which in FIG. 7 is represented as detached from the midsole body 10, is however integrated in the latter. Seen in plan view, the ventilation insert element 68 has a U shape, the two parallel legs 70, 70′ running in the longitudinal direction of the shoe sole S and being connected to one another at their rear end, seen in the walking direction L, by way of an arc portion 72. The two legs 70, 70′ and the arc portion 72 are formed by a cross-sectionally U-shaped channel wall 74, this channel wall 74 a delimiting in the region of the legs 70, 70′ a respective main channel portion 38′. The legs 70, 70′ and the arc portion 72 are open in the upward direction on the side facing away from the outsole 44. The channel wall 74 forms a bottom part 76 as well as an inner wall part 78 and an outer wall part 80, these two wall parts 78, 80 protruding from the bottom part 76 in the upward direction. In the integrated state of the ventilation insert element 68, the exposed upper periphery of the wall parts 78, 80 is in line with the upper surface 42 of the midsole body 10. In the heel region 16, the depth of the U-shaped cross section, measured from the free periphery of the wall parts 78, 80 to the bottom part 76, is preferably at least 4 mm. Furthermore, the wall parts 78, 80 are preferably at a distance from one another of at least 8 mm. In the midfoot region 24, said depth increases in a way corresponding to the form of the heel recess 46 and then decreases continuously, in the direction of the end at the front in the walking direction L.

In the arc portion 72, which in the integrated state comes to lie in the rear portion 14 of the heel region 16, a respective air inlet tube stub 82 protrudes from the outer wall part 80 in the direction of the shoe sole inner side 18 and in the direction of the shoe sole outer side 20. These stubs are flow-connected to the main channel portions 38′ and their outer free ends form the air inlet openings 22.

Correspondingly, in the midfoot region 24 and in the ball/toe region 26, air outlet tube stubs 84 protrude from the outer wall part 80 in the outward direction. These, too, are flow-connected to the assigned main channel portion 38′, form the branch channel portions 40 and, with their free ends, form the air outlet openings 28.

The ventilation insert element 68 is preferably produced from TPU with a Shore A hardness of 85 by the injection-molding process.

FIG. 7 also shows a reinforcing element 86, which has at least in the heel region 16 and midfoot region 24 such a stability that the midsole 12 is at least approximately flexurally rigid, with respect to loads during standing and walking, in its portion located above the soft heel part 48. In the state in which it is integrated in the midsole body 10, the reinforcing element 86 is enclosed by the ventilation insert element 68. Seen in the direction at right angles to the longitudinal direction of the shoe sole S, the reinforcing element 86 is consequently located in a central region of the midsole body 10, one of the two main channel portions 38′ being arranged in the direction of the shoe sole inner side 18 and one in the direction of the shoe sole outer side 20.

The reinforcing element 86, which is likewise preferably produced by the injection-molding process, has an upper, tongue-shaped, plate-like carrying part 88 and a V-shaped supporting part 90, protruding from the latter in the downward direction. Both the carrying part 88 and the supporting part 90 are of a double-walled form, the two walls respectively being fixedly connected to one another by way of ribs 92. In the state in which it is integrated in the midsole body 10, the carrying part 82 lies close to the surface 42, as the midsole body 10 in FIG. 7 indicates; here, the reinforcing element 86 is already integrated in the midsole body 10. It extends between the two legs 70, 70′ from the inner wall part 78 in the arc portion 72 forward in the walking direction L into a front portion of the ball/toe region 26. The reinforcing element 86 is preferably rigidly formed and produced, for example, from nylon 12 in the heel region 16 and the midfoot region 24, while it may be flexibly formed and consist, for example, of TPU in the ball/toe region 26.

The supporting part 90 is likewise stably formed, the rear leg 90′, seen in the walking direction L, of the supporting part 90 being shaped in a way corresponding to the heel recess 46 and this rear leg 90′ meeting the front leg 90″ at the front end, seen in the walking direction L, of the heel recess 46, where it forms a tilting edge 94.

The prefabricated reinforcing element 86 and the prefabricated ventilation insert element 68 may be placed in a cavity of an injection mold for the injection-molding of the midsole body 10, injection of PUR Shore 58 C, for example, taking place after the mold has been closed for the purpose of molding the midsole body 10. In this case, the injection mold may have supporting ribs for the channel wall 74 and slides engaging in the air inlet tube stubs 82 and the air outlet tube stubs 84, in order to prevent the ventilation insert element 68 from being compressed during the injection-molding of the midsole body 10.

As a result of the exploded representation, the midsole body 10 shown in FIG. 7 has depressions and clearances that are formed to match the ventilation insert element 68.

Furthermore, FIG. 7 shows the insole 54, which forms the cover 52 and . . . onto the surface 42 formed by the midsole body 10, possibly the reinforcing element 86 and the exposed face of the outer wall part 80 and inner wall part 78.

Around the periphery, the insole 54 is enclosed by the relatively high bead 50. The carrier layer 58 of the insole 54 is preferably formed in the manner of a footbed and is correspondingly adapted to the thickness of the supporting layer 64. Furthermore, the surface 42 has between the outer wall part 80 and the bead 50 a continuous strip-like surface part 42′, both on the shoe sole inner side 18 and on the shoe sole outer side 20, so that the supporting layer 64 is supported peripherally along the bead 50 by way of the reinforcing element 86 in a wide middle portion over the entire length of the midsole body 10.

FIGS. 8 and 9 show a further possible embodiment of the reinforcing element 86 for a midsole 12 according to FIG. 2 or 3, which is formed with a ventilation channel 30 corresponding to FIG. 1.

In FIG. 10, the reinforcing element 86 is shown in a perspective representation obliquely from above. Its task is precisely the same as that described above in connection with the embodiment according FIG. 7 and known from MBT walking devices. In FIGS. 8 and 9, the outlines of the midsole 12 are indicated and the reinforcing element 86 is shown in a dark color.

In the heel region 16, the sheet-like reinforcing element 86 runs in the midsole body 10 along the heel recess 46 and, in the midfoot region 24 and in a rear portion of the ball/toe region 26, seen in walking direction L, it runs in the interior of the midsole body 10 at a distance below the ventilation channel 30. Since the wall thickness of the midsole body 10 between the heel recess 46 and the surface 42 is much smaller in the heel region 16 than in the midfoot region 24 and the ball/toe region 26, the insertion of the reinforcing element 86 known from MBT walking devices could lead to an inadequate depth of the ventilation channel 30 in the heel portion 32. This is particularly clear from FIG. 9, where the ventilation channel 30 is shown colored gray. In order to counteract the stated disadvantage, the reinforcing element 86 has in the heel region 16 a channel-like recess 96, which is V-shaped in plan view and corresponds to the heel portion 32. In order nevertheless to ensure the necessary flexural rigidity of the reinforcing element 86, it may, for example, have supporting ribs running on the underside along the webs 100 that separate the clearances 98 from one another. Even if they protrude into the soft heel part 48, because of their small height, they do not change the behavior of the shoe sole or the properties thereof. It is also possible to form the reinforcing element 86 in the heel region 16 from a more stable material.

In the case of a shoe sole according to FIG. 7, it is conceivable not to use a ventilation insert element 68, but to mold the depression for forming the main channel portions 38′ and the connection thereof in the arc portion 72 by a rib from the injection mold, and to mold the branch channel portions directly on the midsole body 10 by means of slides.

During walking with a shoe sole shown in the figures and described above, when the heel region 16 is put down during a step, on the one hand the soft heel part 48 is compressed, which greatly reduces shocks on the user's body, and on the other hand the cover 52 in the heel region 16 is also deformed in the direction of the midsole body 10. This leads to a local constriction of the cross section that is delimited by the midsole 10 and the cover 52, or the carrier layer 58 thereof, and is filled with air. As a result of the rolling action on the ground, this constricted cross section is displaced in the walking direction L over the midfoot region 24 into the ball/toe region 26. This shifting of the constriction from the heel region 16 into the ball/toe region 26 leads to the expulsion of air from the ventilation channel 30 through the air outlet openings 38, whereas, after tilting about the tilting edge 94, or the tilting edge formed by the midsole body 10 at the front end of the heel recess 46, the cover 52 or the insole 54 is relieved of load in the heel region 16, which leads to a widening of the cross section again behind the constriction as a result of the elasticity of the cover 52 or the insole 54, whereby fresh air is sucked into the ventilation channel 30 through the air inlet openings 22. During walking, air is consequently made to pass through the midsole 12 in a ventilating manner on the basis of a purely mechanical principle. This warmed-up air is expelled through the air outlet openings 28 while fresh, cool air is sucked in through the air inlet openings 22.

If the cover 52 or the insole 54 is of an air-permeable form, cool air is also correspondingly forced against the user's foot. 

1-13. (canceled)
 14. A shoe sole with a midsole, having a midsole body extending over a heel region, a midfoot region and a ball/toe region, and with an outsole, wherein the midsole body has at least one air inlet opening in the heel region, air outlet openings in the midfoot region and/or the ball/toe region, and also a ventilation channel, which connects the air inlet opening to the air outlet openings and is covered on the side facing away from the outsole by means of a cover, which is elastically compliant, in the direction of the outsole, when under load during walking.
 15. The shoe sole as claimed in claim 14, wherein, in a rear portion, seen in the walking direction, of the heel region there is a respective air inlet opening both on the outer side and on the inner side, and in the midfoot region and/or the ball/toe region there are air outlet openings both on the outer side and on the inner side.
 16. The shoe sole as claimed in claim 15, wherein the ventilation channel has in the heel region a V-shaped heel portion, leading with its legs to the air inlet openings, and in the midfoot region and possibly the ball/toe region has a distributor portion, which adjoins the heel portion and has a central main channel portion and branch channel portions, branching off laterally from the latter and leading to the air outlet openings.
 17. The shoe sole as claimed in claim 14, wherein the ventilation channel has two main channel portions, running at least approximately in the longitudinal direction of the shoe sole and connected to the air inlet openings, branch channel portions branching off from one of the main channel portions to the outer air outlet openings and from the other of the main channel portions to the inner air outlet openings.
 18. The shoe sole as claimed in claim 14, wherein the cover has an insole, which has a carrier layer and, on the side of the carrier layer that is facing the midsole body, an elastically compliant supporting layer.
 19. The shoe sole as claimed in claim 18, wherein the supporting layer has a multiplicity of supporting elements arranged at a distance from one another, protruding from the carrier layer and supported on the midsole.
 20. The shoe sole as claimed in claim 18, wherein the supporting layer has a multiplicity of wave-shaped supporting strips, protruding from the carrier layer and supported on the midsole.
 21. The shoe sole as claimed in claim 18, wherein the supporting layer has a knitted spacer fabric, which is supported on the midsole.
 22. The shoe sole as claimed in claim 14, wherein a soft heel part is arranged in a heel recess of the midsole body, the outsole, in the unloaded state, is kept in a form in which it is rounded in a convex manner in the longitudinal direction of the shoe sole by the midsole body and the soft heel part, and the midsole has in the heel region and in the midfoot region a reinforcing element with such a stability that the midsole is at least approximately flexurally rigid, with respect to loads during standing and walking, in its portion located above the soft heel part.
 23. The shoe sole as claimed in claim 22, wherein the reinforcing element is integrated in the midsole body and has a channel-like recess for the ventilation channel.
 24. The shoe sole as claimed in claim 17, wherein, in the transverse direction of the shoe sole, the reinforcing element in the midsole body is arranged in a central region and one of the main channel portions runs on each side of the reinforcing element.
 25. The shoe sole as claimed in claim 24, wherein a ventilation insert element, which is preferably U-shaped in plan view, is integrated in the midsole body, delimits the main channel portions with a cross-sectionally U-shaped channel wall and has air inlet tube stubs, which protrude from the channel wall in the heel region and are flow-connected to the main channel portions, and air outlet tube stubs, which protrude from the channel wall in the midfoot region and/or the ball/toe region and are flow-connected to the main channel portions.
 26. A walking device with a shoe sole as claimed in claim 14 and an upper arranged on the shoe sole. 